Color constant inks

[tmiller_iluvprinting]

If Epson can produce a stable/color constant ink, why can't ink companies do the same for offset applications? We are constantly having to explain the reason for D50 lighting and the affects of metamerism outside of print standard lighting to customers who complain about "it doesn't match the proof in my office." This is getting old, you would think ink companies would address this to get a leg up on their competition.
Regards,
Todd

[inkedup]

Too many variables involved. Also, a lot of people don't understand colour or how ink and paper can react. I had one customer who rejected a job because the colour did not match his PMS guide. We asked him to bring this copy of the guide with him for the rerun. This guy shows up with his PMS guide, and I ask to see it to compare his guide to ours. He hands me this ratty looking guide from ( this is no lie ) 1986. We had just got new 2008 guides the month before. I brought him press sheets from his last run and showed him that the job that we ran matched our guide and then showed him the difference with his. He said that he didn't care that it matched our copy it didn't match his and he wanted a rerun. To make a long story short, our owner got involved and tried to work something out with him. He settled for a 15% discount and kept the 1st run. We no longer do business with this gentleman.

[gordo]

If Epson can produce a stable/color constant ink, why can't ink companies do the same for offset applications? We are constantly having to explain the reason for D50 lighting and the affects of metamerism outside of print standard lighting to customers who complain about "it doesn't match the proof in my office." This is getting old, you would think ink companies would address this to get a leg up on their competition.
Regards,
Todd

I'm not sure I agree with what you're saying. There is nothing the ink companies can do. Also, I could not find any reference to "color constant" on the Epson website so I don't know what that term means.
None of the inks used by Epson, or in presswork, are exact spectral matches to the media originally used to produce the original art. As a result, in printing, the inks used to create color reproductions are combined to simulate the proof (target artwork) only under one industry standard light source - referred to as "D50" or "D65". Proof and presswork form a metameric pair under those conditions.
What some shops do is to have a customer viewing area where presswork can be examined under different lighting conditions. Of course, when that is done, the proof is not available. I.e. compare proof and presswork under correct lighting - but examine presswork only under non-standard lighting.

best, gordon p

[gordo]

I had one customer who rejected a job because the colour did not match his PMS guide. We asked him to bring this copy of the guide with him for the rerun.

I think this is a preventable failure in communication - and I don't think the customer should be blamed. When a PMS/spot color is specified in the RFQ, I think it is prudent that the printshop confirm with the customer what the target color is for that spot color (i.e. my swatchbook, your swatchbook, an L*a*b* target, a previously printed sample, etc.). It takes just a few seconds for the sales rep or CSR to get clarity. The question can even be built into online RFQ systems.


best, gordon p

[Magnus]

If Epson can produce a stable/color constant ink, why can't ink companies do the same for offset applications? We are constantly having to explain the reason for D50 lighting and the affects of metamerism outside of print standard lighting to customers who complain about "it doesn't match the proof in my office." This is getting old, you would think ink companies would address this to get a leg up on their competition.
Regards,
Todd

Hi Todd, I agree with you! There must be ways to make offset ink less metamerism-sensitive. I dont even think theres any research on the subject. When I speak to a few different ink-suppliers none of them had any clue what I was talking about.

Dont think anyone thought that this would be possible with inkjet 10 years ago either.

Im looking forward to the new "K3 nanotech offset ink"!

[inkedup]

I think this is a preventable failure in communication. When a PMS/spot color is specified in the RFQ, I think it is prudent that the printshop confirm with the customer what the target color is for that spot color (i.e. my swatchbook, your swatchbook, an L*a*b* target, a previously printed sample, etc.). It takes just a few seconds for the sales rep or CSR to get clarity. The question can even be built into online RFQ systems.


best, gordon p

Our salesman brought in the order which asked for 4 colour process and one spot colour PMS Cool Gray # 11 on our house gloss text stock. Our ink company matched the colour and sent proofs and ink. Our salesman contacted the customer to have him sign off on the proofs, and was told to just run the job. We did and that's when the problem began. By the way, the proofs matched our PMS guide. Also we've heard from other printers in the Mississauga area that this fellow has pulled this stunt with other shops before.

[Bret Hesler]

I would be more interested in an inkjet ink using pigments that were similar to those used in litography. We did not have metamerism failure problems with pigment based dot proofs (thermal waterproof, finalproof or polaproof), like we have with inkjet proofs. I compared the spectral response curves of thermal waterproof and finalproof to our litho inks, and they were very close (I guess there is some chance of metameric failure, as they were not identical)

However, inkjet printers are made to produce the widest gamut of colors possible for pretty pictures, and certain manufacturers are quick to kill anything that will eat into their healthy ink profits. Has anyone seen anything coming off the latest inkjet presses, and able to comment on the colorants used?

Bret

[Cold]

There must be ways to make offset ink less metamerism-sensitive.

The sensitivity is not in the pigment used in an off-set ink nor in a dye colorant used in another application. The metameric effect comes in the difference between the two chemistries and there spectral responses to various light sources.

[tmiller_iluvprinting]

Gordon-
Color Constancy-is an example of subjective constancy and a feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions.
I do not believe that the ink producers can't do anything about this. Epson did when they switched to the K3
inkset. Compare an image proofed on an Epson 9600 to the same image proofed on an Epson 9880 under
3200º lighting, especially a gray balance sensitive image and you will see what I am talking about.
I think Magnus said it best, bring on the K3 offset ink, or bring on the inkjet press!
Regards,
Todd

[gordo]

Gordon-
Color Constancy-is an example of subjective constancy and a feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions.
I do not believe that the ink producers can't do anything about this. Epson did when they switched to the K3
inkset. Compare an image proofed on an Epson 9600 to the same image proofed on an Epson 9880 under
3200º lighting, especially a gray balance sensitive image and you will see what I am talking about.
I think Magnus said it best, bring on the K3 offset ink, or bring on the inkjet press!

Hi Todd, I'm very familiar with color constancy in human perception. However that is not what you wrote in your original post. You wrote: "Color constant inks - If Epson can produce a stable/color constant ink, why can't ink companies do the same for offset applications?" So, you wrote about inks and pigments (which is what I responded to) not human perception.
I am not in a position to "Compare an image proofed on an Epson 9600 to the same image proofed on an Epson 9880 under 3200º lighting" perhaps you can clarify what you mean and how you think ink manufacturers are failing to address an attribute of human vision.

thx, gordon p